Be sure all the ingredients are at room temperature before you begin. In a clean, dry bowl, whisk the egg yolk, salt and pepper steadily with a small balloon whisk, fork or wooden spoon. When the egg is pale yellow and smooth, begin to add the oil one drop at a time and very slowly. Keep dripping in the oil and never stop whisking. When it becomes too thick to whisk easily, begin to alternate drops of lemon juice or vinegar with the oil. Remember that oil will thicken the sauce and lemon juice or vinegar will dilute it. When you have used up all the ingredients, the sauce is ready.
Be sure all the ingredients are at room temperature before you begin. Put the egg in the food processor, using the blade attachment. Whizz until the egg is completely blended and pale yellow. Dribble in the oil very slowly, but don’t stop the machine. Keep going until the sauce is smooth and thick. Add the lemon juice or vinegar, whizz for a few seconds longer to blend it perfectly, then switch off. Transfer the sauce to a bowl or sauce boat and use as required.
© 1990 Valentina Harris. All rights reserved.